Evolution and protein structure Flashcards
DNA replication is essential for…
the transmission of genome between generations
Mutations
Errors in DNA replication
Mutation can be passed on to the next generation
changes in reproductive cells
phenotypic changes are…
subject to selection
protein domains
several dozen amino acids long
- distinct structural and/or functional units in a protein
- usually respond to particular function or interaction, contributing to overall role of protein
similar domains can be found…
on proteins with different functions
how long are sequence features?
2/3 amino acids long (small)
Sequence Features
groups of amino acids that confer certain characteristics upon a protein and its function
Examples of parts of a protein sequence features convey characteristics upon
active sites, binding sites, post-transitional modification sites, repeats
how can you show 2 proteins are homologous? (evolutionary)
Protein sequence alignment
Amino-acid sequence alignment
synonymous mutations
do not change an amino-acid
… due to degenerate nature of the DNA code
non-synonymous mutations
changes an amino-acid
Why are amino-acids not equally “swappable”?
depends on how similar their properties are
does not affect protein in drastic way if similar
pseudogenes
- exact sequence as gene in genome
- nothing to regulate production
- would never really produce any protein (can’t transcribe)
what principal belief is the idea of the molecular clock based upon?
mutations accumulate at a constant rate (in non-coding DNA)
